TOPIC: security question stays blank (captcha)

I upgraded from 1.9 Limesurvey to version 2.
Some surveys I have running request an answer to the security question on the first page before giving access to the survey questions.
The text of this question (a sum) has disappeared completely. A correct answer is still needed to get access. This completely stops the respondents.

I checked the forum and found that is is necessary to set filter html on XSS to No; so I did that. No effect at all.